From a security standpoint, confidential information handled by a computer system is beneficially protected to ensure that the confidential information is not accessed (i.e., read or written to) only by specific trusted programs (hereinafter, secure programs) and not by any program that is not trusted (hereinafter, non-secure programs).
For this purpose, the computer system has a specific area of memory for storing the confidential information (hereinafter, secure area) and an access controller that allows access to the secure area only when a predetermined condition for allowing access is met. Thus, the access controller limits access so that access is allowed only while the secure program is being executed.
Technology for controlling a program execution period is known, such as conventional technology in which a computer system includes a plurality of processors (hereinafter, a parallel computer system) and performs parallel execution of a plurality of program units (e.g., Cited Publication 1).